Re: Upgrades with no downtime

From: LS Cheng <exriscer_at_gmail.com>
Date: Tue, 27 Oct 2009 20:16:33 +0100
Message-ID: <6e9345580910271216l243f2683j1cea0c249613186a_at_mail.gmail.com>

And exactly that was my point since it's going to replace Streams (or looks like it)

Regards

--
LSC


On Tue, Oct 27, 2009 at 6:14 PM, SHEEHAN, JEREMY <
JEREMY.SHEEHAN_at_nexteraenergy.com> wrote:



>  GoldenGate was just purchased by Oracle.

>

>

>

> Jeremy

>

> P *Consider the environment. Please don't print this e-mail unless you

> really need to.*

>

>

>

> *From:* oracle-l-bounce_at_freelists.org [mailto:

> oracle-l-bounce_at_freelists.org] *On Behalf Of *LS Cheng

> *Sent:* Tuesday, October 27, 2009 11:19 AM

> *To:* valpis_at_gmail.com

> *Cc:* Oracle Discussion List

> *Subject:* Re: Upgrades with no downtime

>

>

>

> Hi

>

> You can probably have a look at GoldenGate, they have been claiming Zero

> Downtime is possible

>

>

> --

> LSC

>

> On Tue, Oct 27, 2009 at 2:44 PM, Johan Eriksson <valpis_at_gmail.com> wrote:

>

> Hi

>

> We had an discussion about how we could solve the problem with no

> downtime during upgrades and I want to know if anyone of you have had

> an similiar problem before and if you could help me with some advice

> on how to solve this.

>

> Our current setup is we have some application servers with most of the

> logic, and in the database we have some pl/sql logic and the data.

>

> The problem we have is when we have an deployment of code or changes

> in the database we also need to take down the system since we can't

> make changes in the tables for example.

>

> My first thought is that we should split the logic and data in the

> database into different schemas, and let the logicschema has views

> that points to the physical storage of the data in another schema. By

> doing this we could have several schemas with logic( and views) in the

> database and we could make changes on the tables without affecting the

> logic. (We rarely deletes any columns and if we do we have to face

> downtime). And by doing this we could make the changes to the tables

> and create a new schema with logic and then this is done we shift the

> application servers to the new schema, and if we also have changes in

> the code in the application servers we take down couple of the

> application servers and commit the changes, bring them up and make the

> run against the new schema and then we are done we take the rest of

> the application servers. We will not have perfectly smooth upgrades by

> doing this since we will loose connections when we switch, but we

> won't have an hour long downtime.

>

> Don't like the idea on using views like this, this is only my first

> thought about it.

>

> I don't think we are the first ones to hit this problem, but how has

> others solved them? I look forward to your suggestions and comments

> about this.

>

> /johan

> --

> http://www.freelists.org/webpage/oracle-l

>

>

>


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Received on Tue Oct 27 2009 - 14:16:33 CDT